1. Field of the Invention
The present invention generally relates to a particulate filter system for a vehicle and a method of controlling the same, and more particularly, to a particulate filter system for a vehicle, which is equipped with a bypass air line branching off from a throttle body so as to be able to smoothly regenerate a particulate filter regardless of operation of an engine, and a method of controlling the same.
2. Description of Related Art
In general, a vehicle using an engine (hereinafter, referred to as a vehicle) inevitably exhausts particulate matter such as soot. The exhaust gas of the vehicle contains a large quantity of particulate matter composed of carbon, unburned hydrocarbon, etc. due to incomplete combustion of fuel. This particulate matter is known to cause a human being a disease such as lung cancer. As such, various plans for regulating emissions of the particulate matter and reducing the particulate matter have been developed throughout the world. As one of technologies that remove this particulate matter, post-treatment technology of the particulate matter is primarily used.
As the post-treatment technology that is most widely used at present, a particulate filter (PF) having a porous filter is mounted on an exhaust manifold of the vehicle so as to collect exhausted particulate matter.
The PF collects the particulate matter exhausted from the engine through the use of a filter, and then burns off the collected particulate matter. Thereby, the filter is regenerated for repetitive use. Thus, this filter regeneration must be completed so as to enable the filter to collect the particulate matter again by burning off the particulate matter collected by the PF as soon as possible. At this time, a control technique for preventing the filter from being overheated and damaged by the regeneration is important. This type of filter regeneration is essentially supplied with oxygen because it burns off the collected particulate matter.
Meanwhile, in order to serve environmental protection not only by improving fuel efficiency but also by reducing the exhaust gas, a so-called idle stop and go (ISG) function has recently been used for allowing the engine to stop operating when a vehicle is stopped for instance while waiting for the green light and to be immediately operated again when the vehicle starts.
However, the oxygen required for the filter regeneration is supplied by oxygen existing in the exhaust manifold. As such, in the state in which the engine stops operating, the oxygen is not naturally supplied from the exhaust manifold. Although such an ISG function is activated to cause the engine to be stopped, it is necessary to carry out the filter regeneration. To this end, an air passage connected between the exhaust manifold and the outside is separately formed, and an oxygen supply means including, for instance a blower, an air control valve, etc., is provided so as to allow air to be introduced through the air passage. Thereby, the oxygen for the filter regeneration is supplied.
This PF of the vehicle is separately equipped with the air passage connected to the exhaust manifold and the outside, the blower and air control valve for controlling flow of the air, etc., so that the vehicle suffers from a complicated structure and an increase in the cost of production.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.